1/3
1 Year of Service
This is the wayIf just one of them is really good and the other doesn't actively get in the way, then the entire game is really good. At one end there is games like Eternum that would still be absolutely great even if they had no sex at all. At the other end there are mindless sex fests such as A Day at the Spa or in even more pure form the original Fallen Doll, which is just an astonishingly good 3D sex simulator with no story whatsoever.
Of course games that get both aspects right while being outstanding for at least one of them, are particularly great. IMO this includes Eternum (outstanding for story, great for the sex) and Stormside (outstanding for the sex, great for story).